Fix a false positive for Style/SafeNavigation

This PR fixes the following error for `Style/SafeNavigation`
when checking `foo&.empty?` in a conditional.

```console
% cat example.rb
do_something if ENV['VERSION'] && ENV['VERSION'].empty?

% bunble exec rubocop -a example.rb --only Style/SafeNavigation,Lint/SafeNavigationWithEmpty
(snip)

Inspecting 1 file
W

Offenses:

example.rb:1:17: W: [Corrected] Lint/SafeNavigationWithEmpty: Avoid
calling empty? with the safe navigation operator in conditionals.
do_something if ENV['VERSION']&.empty?
                ^^^^^^^^^^^^^^^^^^^^^^
example.rb:1:17: C: [Corrected] Style/SafeNavigation: Use safe
navigation (&.) instead of checking if an object exists before calling
the method.
do_something if ENV['VERSION'] && ENV['VERSION'].empty?
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

0 files inspected, 2 offenses detected, 2 offenses corrected
Infinite loop detected in
/Users/koic/src/github.com/koic/rubocop-issues/rails/example.rb.
/Users/koic/src/github.com/rubocop-hq/rubocop/lib/rubocop/runner.rb:289:in
`check_for_infinite_loop'
/Users/koic/src/github.com/rubocop-hq/rubocop/lib/rubocop/runner.rb:272:in
`block in iterate_until_no_changes'
/Users/koic/src/github.com/rubocop-hq/rubocop/lib/rubocop/runner.rb:271:in
`loop'
/Users/koic/src/github.com/rubocop-hq/rubocop/lib/rubocop/runner.rb:271:in
`iterate_until_no_changes'
/Users/koic/src/github.com/rubocop-hq/rubocop/lib/rubocop/runner.rb:242:in
`do_inspection_loop'
```

I found it with the following code.
https://github.com/rails/rails/blob/v6.0.3.2/activerecord/lib/active_record/railties/databases.rake#L120

CHANGELOG.md

@@ -12,6 +12,7 @@
 * [#8572](https://github.com/rubocop-hq/rubocop/issues/8572): Fix a false positive for `Style/RedundantParentheses` when parentheses are used like method argument parentheses. ([@koic][])
 * [#8653](https://github.com/rubocop-hq/rubocop/pull/8653): Fix a false positive for `Layout/DefEndAlignment` when using refinements and `private def`. ([@koic][])
 * [#8655](https://github.com/rubocop-hq/rubocop/pull/8655): Fix a false positive for `Style/ClassAndModuleChildren` when using cbase class name. ([@koic][])
+* [#8654](https://github.com/rubocop-hq/rubocop/pull/8654): Fix a false positive for `Style/SafeNavigation` when checking `foo&.empty?` in a conditional. ([@koic][])
 
 ### Changes
 

docs/modules/ROOT/pages/cops_style.adoc

@@ -8653,6 +8653,10 @@ foo && foo.nil? # method that `nil` responds to
 foo && foo < bar
 foo < bar if foo
 
+# When checking `foo&.empty?` in a conditional, `foo` being `nil` will actually
+# do the opposite of what the author intends.
+foo && foo.empty?
+
 # This could start returning `nil` as well as the return of the method
 foo.nil? || foo.bar
 !foo || foo.bar

lib/rubocop/cop/style/safe_navigation.rb

@@ -49,6 +49,10 @@ module Style
       #   foo && foo < bar
       #   foo < bar if foo
       #
+      #   # When checking `foo&.empty?` in a conditional, `foo` being `nil` will actually
+      #   # do the opposite of what the author intends.
+      #   foo && foo.empty?
+      #
       #   # This could start returning `nil` as well as the return of the method
       #   foo.nil? || foo.bar
       #   !foo || foo.bar
@@ -104,6 +108,7 @@ def check_node(node)
           # chain greater than 2
           return if chain_size(method_chain, method) > 1
           return if unsafe_method_used?(method_chain, method)
+          return if method_chain.method?(:empty?)
 
           add_offense(node) do |corrector|
             autocorrect(corrector, node)

spec/rubocop/cli/cli_autocorrect_spec.rb

@@ -1581,6 +1581,24 @@ def self.some_method(foo, bar: 1)
     RUBY
   end
 
+  it 'does not crash Lint/SafeNavigationWithEmpty and offenses and accepts Style/SafeNavigation ' \
+     'when checking `foo&.empty?` in a conditional' do
+    create_file('example.rb', <<~RUBY)
+      do_something if ENV['VERSION'] && ENV['VERSION'].empty?
+    RUBY
+    expect(
+      cli.run(
+        [
+          '--auto-correct',
+          '--only', 'Lint/SafeNavigationWithEmpty,Style/SafeNavigation'
+        ]
+      )
+    ).to eq(0)
+    expect(IO.read('example.rb')).to eq(<<~RUBY)
+      do_something if ENV['VERSION'] && ENV['VERSION'].empty?
+    RUBY
+  end
+
   it 'corrects TrailingCommaIn(Array|Hash)Literal and ' \
      'Multiline(Array|Hash)BraceLayout offenses' do
     create_file('.rubocop.yml', <<~YAML)

spec/rubocop/cop/style/safe_navigation_spec.rb

@@ -90,6 +90,10 @@
     expect_no_offenses('foo && foo.bar !~ /baz/')
   end
 
+  it 'allows an object check before a method call that is used with `empty?`' do
+    expect_no_offenses('foo && foo.empty?')
+  end
+
   it 'allows an object check before a method call that is used in ' \
      'a spaceship comparison' do
     expect_no_offenses('foo && foo.bar <=> baz')